Stabilized gasoline antiknock compositions and gasoline containing same



United States Patent 3,261,674 STABILIZED GASOLINE ANTIKNOCK COMPOSI- TIONS AND GASOLINE CONTAINING SAME Albert C. Condo, Jr., Newtown Square, Pa., assignor to The Atlantic Refining Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Filed Mar. 10, 1961, Ser. No. 94,686 12 Claims. (Cl. 44-69) This invention relates to improved fuel for spark ignition internal combustion engines and to additive compositions for such fuel. More particularly, this invention relates to gasoline compositions containing a cyclopentadienyl manganese tricarbonyl antiknock agent and a betadiketone.

Recently there :hasbeen developed a new class of organometallio antiknock agents for gasoline fuels employed in spark ignition internal combustion engines. These agents are the cyclopentadienyl manganese tricarbonyls. The synthesis of the cyclopentadienyl manganese tricarbonyls, the use of such compounds as antiknock agents for gasoline fuels, and other gasoline additives that can be associated therewith are set forth in US. Patents No. 2,818,416, No. 2,818,417, and No. 2,870,180. A considerable amount of antiknock data have been obtained on the methyl cyclopentadienyl manganese tricarbonyl compound the synthesis of which is described in Example II of the aforementioned Patent No. 2,870,- 180. These antiknock data are reported in the article by I. E. Brown and W. G. Lovell, entitled A New Manganese Antiknock, in Industrial and Engineering Chemistry, volume 50, page 1547, et seq. (1958). These data show that, in particular, methyl cyclopentadienyl manganese tricarbonyl may be utilized as the sole antiknock agent in commercial motor gasolines and also that such manganese antiknock agents can be used in combination with lead alkyl antiknock agents, in particular tetraethyl lead. Moreover, it Was found that the manganese antiknock compound exhibited a particularly marked synergistic effect on the antiknock characteristics of the gasoline when small amounts, i.e. from 0.1 to 0.5 gram of manganese in the form of the methyl cyclopentadienyl manganese tricarbonyl per gallon of gasoline, are used in conjunction with 2 or 3 milliliters of tetraethyl lead per gallon of gasoline.

It has been found, however, that although the cyclopentadienyl manganese tricarbonyls will not decompose and will remain in solution in gasoline as long as they or the gasoline containing them is not exposed to radiation such as sunlight, they are unstable in the presence of radiation such as sunlight and will decompose or will precipitate out of the gasoline in the form of a darkcolored precipitate, generally a dark brown precipitate. Moreover, if the manganese compound is utilized in a gasoline containing a lead antiknock agent such as tetraethyl lead, this instability also causes a white precipitate of lead to form on top of the dark brown precipitate. This is particularly surprising since tetraethyl lead is stable in gasoline in the presence of sunlight over relatively long periods of time when there is no cyclopentadienyl manganese tricarbonyl compound present in the gasoline.

It has now been found that the cyclopentadienyl manganese tricarbonyls can be inhibited against a precipitateforming decomposition reaction resulting from exposure to sunlight by incorporating a beta diketone in the cyclopentadienyl manganese tricarbonyl and the cyclopentadienyl manganese tricarbonyls can be retained in solution in gasoline in the presence of sunlight if a beta-diketone is also contained in the gasoline.

3,261,674 Patented July 19, 1966 "ice It is an object of this invention, therefore, to provide a stable antiknock additive for spark ignition internal combustion engine fuels.

It is another object of this invention to provide a stable antiknock additive containing a cyclopentadienyl manganese tricarbonyl antiknock agent and a beta diketone for spark ignition internal combustion engine fuels.

It is another object of this invention to provide a stable antiknock additive containing a lead alkyl antiknock agent, a cyclopentadienyl manganese tricarbonyl antiknock agent, and a beta-diketone for spark ignition internal combustion engine fuels.

It is another object of this invention to provide a fuel composition for use in spark ignition internal combustion engines containing a cyclopentadienyl manganese tricarbonyl antiknock agent and a beta-diketone.

It is another object of this invention to provide a fuel composition for use in spark ignition internal combustion engines containing a lead alkyl antiknock agent, a cyclopentadienyl manganese tricarbonyl antiknock agent and a beta diketone.

Other objects of this invention will be apparent from the detail description of the invention and the claims that follow.

In accordance with this invention from 1 to 3 moles of a hydrocarbon oil soluble beta diketone Will inhibit one mole of a cyclopentadienyl manganese tricarbonyl antiknock agent against a precipitate-forming decomposition reaction resulting from exposure to radiation such as sunlight. Further, in accordance with another embodiment of this invention, from 1 to 3 moles of a hydrocarbon oil soluble beta diketone per mole of cyclopentadienyl manganese tricarbonyl antiknock agent when added to a stable gasoline containing the cyclopentadienyl manganese tricarbonyl antiknock agent will prevent the manganese compound from precipitating out of solution when suchgasoline is exposed to radiation such as sunlight. The hydrocarbon oil soluble beta diketones of this invention are characterized by having the structural formula wherein R and R are hydrocarbon radicals selected from the group consisting of alkyl,'aryl, alkaryl and aralkyl radicals containing from 1 to 20 carbon atoms and wherein R and R may be the same or different. As used herein, the term hydrocarbon oil includes gasoline boiling range hydrocarbon fractions, light naphtha fractions and the like. The gasoline may also contain other additives, in particular, a lead alkyl antiknock agent such as tetraethyl lead, in addition to the cyclopentadienyl manganese tricarbonyl compound, without afifecting the stabilizing proper-ties of the beta-diketone or the manganese compound.

The stable gasoline fuel to which the antiknock compositions of this invention are added is a petroleum fraction boiling in the gasoline hydrocarbon range, i.e. between about 50 F. and about 450 F., and which gasoline fuel is relatively stable with respect to oxidation or gum formation. The stability may result from the use of stable base stocks such as alkylate, reformate and the like which have been highly refined to remove olefins, or the stability may result from the use of conventional oxidation inhibitors. In addition, such fuels may contain conventional anti-rust additives, carburetor anti-icing additives, pre-ignition inhibitors such as the phosphorus compounds, dyes, and similar compounds which are conventionally added to gasoline.

The gasoline may also contain from 0.1 gram to 6.3 grams of lead per gallon, the lead being in the form of an organo-lead, antiknock agent such as lead alkyl, for example, tetra-ethyl lead, tetra-methyl lead, tetra-methylethyl lead, tetra-isopropyl lead and the like. In addition to the lead compound, the lead antiknock agent contains 4 EXAMPLE I In order to demonstrate the criticality of the beta diketones as the class of compounds which inhibit radiation induced precipitate-forming decomposition reactions of the usual scave.nging. agents Such as ethylene dibromide 5 the cyclopentadienyl manganese tricarbonyls, the comand ethylene d1chl9nde' parisons shown in Table I were made on gasoline solu- The cyclopentadienyl manganese tricarbonyl anti nock tions prepared as has been described agent such as the cyclopentadlenyl manganese tricarbonyl or the alkyl cyclopentadienyl manganese tricarbonyl, for T able I example, the methyl cyclopentadienyl compound, is added y hill to the gasoline in amounts such that the manganese of the InhibitOr compound testfidl PP pp cyclopentadienyl manganese tricarbonyl compound ranges BlaHkI10 inhibitor 8 from 0.1 gram to 6.3 grams per gallon of the gasoline. 2,3-bl1tanedi0ne alpha-diketone) 8 The amount of oil soluble beta diketone required to be 2,5-heXanedi0he gamma-diketone) 8 added together with the manganese compound ranges be- 2,4-PeI1iamdi0nB beta-diketone) 1041 tween 1 mole and 3 moles per mole of the cyclopenta- Isovaleryl acetonfi beta-diketone) 1 dienyl manganese tricarbonyl. Di yl malonate 8 In another embodiment of the invention the cyclopen- E hyl acetoacetate 3 tadienyl manganese tricarbonyl antiknock agent is com- Dim yl maleate 10 bined with the lead alkyl antiknock fluid to give a com- Di yl OXalate 6 billation ahtiknock agent for addition to gasolihe- In 1 No precipitate observable after 21 days, test discontinued. these Compositions i116 Weight ratio of the manganese of These data show that the beta diketones are superior the cyclopentadienyl mangahfise h'icarhohyl compound to to the other classes of diketones and to compounds havthe lead of the lead alkyl ranges from 1:63 to 1:1 and m Structures Similar to the diketones preferably from 1:24 to 1:2 in order to obtain the desired 25 octane appreciation. In these compositions the mole ratio EXAMPLE H of the beta diketone inhibitor to the manganese compound A number of oil soluble beta-diketones representative ranges from 1:1 to 3:1 in order to prevent the manganese of various types of groups attached to the diketone nucompound from decomposing and precipitating out of cleus were tested in the same manner as described for solution when such composition is exposed to sunlight. Example I. The solutions were allowed to stand in day- A test was developed in order to demonstrate the effeclight for 21 days and then they were filtered and the tiveness of the oil soluble beta diketones of this invention amount of precipitate per 100 cc. of solution was deteras compared with other diketones and similar compounds mined. The results are shown in Table II. for inhibiting the radiation induced decomposition of the T bl II cyclopentadienyl manganese tricaibonyls.

A premium type grade gasoline comprising hydrocar' bons in the boiling range between 90 F. and 400 F. B diketonetested Days until gt; obtained by blending products predominantly from catpp pp a e vfsolution alytic cracking, catalytic reforming and alkylation and after 21 days containing 3 cc. of tetraethyl lead per gallon to give a fuel 40 Blank minhibim 8 70 having an octane number of 100 by the ASTM Method 2,4-peiitanedione 11 17.5 P908 was selected as the gasoline component for the var- 1 3 lOllS compositions to be compared. The desired quantity 5,5-dimethylhexanedione 16 23 of methyl cyclopentadienyl manganese tricarbonyl was 1133 9 gfi$ fgf$g lg added to the gasoline component. In Examples I and II Diisovaleryl methane 10 27 this amount corresponded to 0.5 gram of manganese per gallon of gasoline. The desired amount of each com- N0 ppt. after 21 days, test discontinued. P d to he for inhibition was then added to the These data show that a wide variety of oil soluble beta gasohhe Contalhlng the manganese compound- In diketones are excellent inhibitors for preventing the preamples I and II thls amount corfsponded 3 moles P cipitation of decomposed cyclopentadienyl manganese tri- 111016 of methyl cyclopehtadlhhyl manganese carbonyls contained in gasoline exposed to daylight. bonyl for the individual compositions to he COmRaTCd- They also show that not all of these compounds have the In Examples III, and IV The individual COmPOSI'tiOHS same inhibiting properties and that isovaleryl acetone is were placed in stoppered, clear glass bottles and exposed particularly preferred to diffuse daylight in the laboratory. In Examples I and II they were observed each day and the time when the EXAMPLE HI first precipitate appeared was noted. The leaded gasoline Several additive compositions were prepared and tested component without the addition of any cyclopentadienyl by allowing them to stand in stoppered, clear glass bottles manganese tricarbonyl compound or beta diketone reexposed to laboratory daylight. They were observed mained completely clear upon exposure to the laboratory after one day and again after seven days exposure. The daylight and no precipitate formed. compositions and results are set forth in Table III.

Table III Composition After one day After seven days Methyl cyclopentadienyl manganese tricarbonyl Some precipitate Heavy, dark precipitate.

Clear, no preoipitate Clear, no precipitate.

Methyl cyclopentadienyl manganese tricarbonyl. Isovaleryl acetone in an amount corresponding to 1 mole per mole of the manganese compound.

Very slightly darkened Dark, no precipitate.

These tests demonstrate that stable compositions for addition to gasoline may be prepared containing the cyclopentadienyl manganese tricarbonyl antiknock agent and the beta diketone.

6 this stability was not affected by the presence of the inhibitor compound. The data also show that it is necessary to employ at least a 1:1 mole ratio of the beta diketone inhibitor to the cyclopentadienyl manganese tricar- EXAMPLE IV 5 bonyl compound to provide protection against the precipi- The same gasoline base fuel containing 3 cc. of tetrat'ateformmg decomposmon Ramon? of the maltgansse ethyl lead per gallon employed in Examples I and II was compound. It has been found that higher mole rat-s, 1.e. used to make up a series of solutions to show the effect of above 3: i do not glve added lnhlbltlon to the inhibitors of this invention on octane number of the mcreased cost of 511155 Such larger amounts of gasoline. The octane numbers were measured by ASTM 10 the Method D1656-60T. Methyl cyclopentadienyl man- I 012111111 ganese tricarbonyl at two different manganese levels were A ccmposltlon adapted use as a stable antlikllock tested with and without isovaleryl acetone inhibitor under a dd t-ive for spark ignition internal combustion engine the conditions and with the results shown in Table IV. fuels consisting essentially Otf methyl cyclopentadienyl Table IV Mole ratio Iso- Observation Octane Gms. Mn., valeryl Ace- Days Storage at end of Number Per Gal. tone to Mn. Stored Condition Storage Period After Compound Storage 7 Darkness Clear, no ppt 102.5 7 Daylight Dark brown ppt 100.4 7 ...do Clear, no ppt 102.0 10 Darkness..- 0 103.4 10 Day1ight Dark brown ppt.. 101.9 10 do Clear, no ppt 102.6

This precipitate analyzed and found to contain 20.3 weight percent manganese, 3.0 weight percent lead, 23.0 weight percent carbon and 3.8 weight percent hydrogen.

These data show that no precipitate forming decompcsimangenese tricarbonyl and a hydrocarbon oil soluble beta tion reactions occur if the gasoline containing the methyl cyclopentadienyl tricarbonyl with no inhibitor is stored in the dark. Moreover, the octane appreciation above the 100 octane number value for the loaded base gasoline re mains normal for the quantities of methyl cyclopentadienyl tricarbonyl employed. The data also show that if the gasoline containing the methyl cyclopentadienyl tricarbonyl is exposed to daylight with no inhibitor, the manganese compound precipitates and the octane number appreciation due to synergistic effect of the manganese compound is greatly reduced. If, however, a hydrocarbon oil soluble beta diketone inhibitor is employed with the cyclopentadienyl manganese tricarbonyl compound the manganese compound does not precipitate in the presence of daylight and the octane number appreciation due to the synergistic action of the manganese compound is retained with only minor reductions.

EXAMPLE V Several solutions were prepared in the same base gasoline as that employed in Examples I, II, and IV. These solutions were stored in stoppered, glass bottles, but instead of being exposed to ordinary diffuse daylight in the laboratory as in the previous examples, they were exposed to direct, intense sunlight. The compositions tested and the results observed are shown in Table V. The manganese compound was methyl cyclopentadienyl tricarbonyl and the inhibitor was isovaleryl acetone in all solutions where such compounds were employed.

diketone characterized by having the structural formula 0 But-CHALK wherein R and R are hydrocarbon radicals selected from the group consisting of alkyl, aryl, alkaryl and aralkyl radicals containing from 1 to 20 carbon atoms, the beta diketone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

2. A composition adapted for use as a stable antiknock additive for spark ignition internal combustion engine fuels consisting essentially of methyl cyclopentadienyl manganese tricarbonyl antikn-ock agent and isovaleryl acetone, the isovaleryl acetone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl antiknook agent.

3. A composition adapted for use as a stable antiknock additive for spark ignition internal combustion engine fuels consisting essentially of a lead alkyl anti-knock agent, methyl cyclopentadienyl manganese tricarbonyl antiknoc-k agent and a hydrocarbon oil soluble beta-diketone characterized by having the structural formula II R-CCH2CR wherein R and R are hydrocarbon radicals selected from the group consisting of alkyl, aryl, al-karyl and arakyl radicals containing from 1 to 20 carbon atoms, the methyl Table V Mole ratio Appearance Gms. Mn., Inhibitor Inhib. to

Per Gal. Mn. Compd.

After 2 days Exposure After 8 days Exposure Clear, no ppt Clear, no ppt.

( do Do.

Large amount dark brown pp Large amount dark brown ppt.

3:1 Clear, no ppt Clear, no ppt. 1:1 S1. cloudy solution Small to medium amount of ppt. 1:2 Small amount of ppt Large amount of dark brown ppt.

1 0.98 gm. per gal.

These data show that the base gasoline component was cyclopentadienyl manganese tricarbonyl being present in stalble in the presence of direct, intense sunlight and that an amount such that the weight ratio of the manganese 7 to the lead of the lead alkyl ranges from 1:63 to 1:1 and the beta diketone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

4. The composition of claim 3, wherein the weight ratio of the manganese of the methyl cyclopentadienyl manganese tricarbonyl to the lead of the lead alkyl ranges from 1:24 to 1:2 and the beta-diketone ranges from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

5. A composition adapted for use as a stable antiknock additive for spark ignition internal combustion engine fuels consisting essentially of tetraethyl lead antiknock agent, methyl cyclopentadienyl manganese tricarbonyl antiknock agent and a hydrocarbon oil soluble beta-diketone characterized by having the structural formula wherein R and R are hydrocarbon radicals selected from the group consisting of alkyl, aryl, alkaryl and aralkyl radicals containing from 1 to 20 carbon atoms, the methyl cyclopentadienyl manganese tricarbonyl being present in an amount such that the weight ratio of the manganese to the lead of the tetraethyl lead ranges from 1:63 to 1:1 and the beta diketone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

6. The composition of claim 5 wherein the weight ratio of the manganese of the methyl cyclopentadienyl manganese tricarbonyl to the lead of the tetraethyl lead ranges from 1:24 to 1:2 and the beta diketone ranges from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

7. A composition adapted for use as a stable antiknock additive for spark ignition internal combustion engine [fuels consisting essentially of tetraethyl lead antiknock agent, methyl cyclopentadienyl manganese tricarbonyl antiknock agent and isovaleryl acetone, the methyl cyclopentadienyl manganese tricarbonyl being present in an amount such that the weight ratio of the manganese to the lead of the tetraethyl lead ranges from 1:63 to 1:1 and the isovaleryl acetone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

8. The composition of claim 7 wherein the weight ratio of the manganese of the methyl cyclopentadienyl manganese tricarbonyl to the lead of the tetraethyl lead ranges from 1:24 to 1:2 and the isovaleryl acetone ranges from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

9. A fuel composition for use in spark ignition internal combustion engines consisting essentially of a petroleum fraction boiling in the gasoline hydrocarbon range, which gasoline fuel is stable toward gum formation and a stable iantiknock composition consisting essentially of methyl cyclopentadienyl manganese tricarbonyl and a hydrocarbon oil soluble beta-diketone characterized -by having the structural formula wherein R and R are hydrocarbon radicals selected from the group consisting of alkyl, aryl, alkaryl and aralkyl radicals containing from 1 to 20 carbon atoms, the manganese of the methyl cyclopentadienyl manganese tricar- Ibonyl ranging in an amount from 0.1 gram to 6.3 grams per gallon of gasoline and the beta-diketone being present in an amount ranging tfirom 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

10. A fuel composition for use in spark ignition internal combustion engines consisting essentially of a petroleum fraction boiling in the gasoline hydrocarbon range, which gasoline fuel is stable toward gum-formation and a stable antiknock composition consisting essentially of methyl cyclopentadienyl manganese tricarbonyl and isovaleryl acetone, the manganese of the methyl cyclopentadienyl manganese tricarbonyl ranging in an amount from 0.1 gram to 6.3 grams per gallon of gasoline and the isovaleryl acetone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

11. A fuel composition for use in spark ignition internal combustion engines consisting essentially of a petroleum fraction boiling in the gasoline hydrocarbon range, which gasoline fuel is stable toward gum-formation and a stable antiknock composition consisting essentially of a lead alkyl antiknock agent, methyl cyclopentadienyl manganese tricarbonyl antiknock agent, and a hydrocarbon oil soluble beta-diketone characterized by having the structural formula wherein R and R are hydrocarbon radicals selected from the group consisting of alkyl, aryl, alkaryl and a'ralkyl radicals containing from 1 to 20 carbon atoms, the lead of the lead alkyl anti-knock agent ranging from 0.1 gram to 6.3 grams per gallon of gasoline, the manganese of the methyl cyclopentadienyl manganese tricarbonyl ranging in an amount from 0.1 gram to 6.3 grams per gallon of gasoline and the beta-diketone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

12. A fuel composition for use in spark ignition internal combustion engines consisting essentially of a petroleum fraction boiling in the gasoline hydrocarbon range, which gasoline fuel is stalble toward gum-formation and a stable .antiknock composition consisting essentially of a lead alkyl antiknock agent, methyl cyclopentadienyl manganese tricarbonyl antiknock agent, and isovaleryl acetone, the lead of the lead alkyl antiknock agent ranging from 0.1 'gram to 6.3 grams per gallon of gasoline, the manganese of the methyl cyclopentadienyl manganese tricarbonyl ranging in an amount from 0.1 gram to 6.3 grams per gal- 1011 of gasoline and the isovaleryl acetone being present in an amount ranging from 1 mole to 3 moles per mole of the methyl cyclopentadienyl manganese tricarbonyl.

References Cited by the Examiner UNITED STATES PATENTS 2,176,747 10/1939 Schneider et a1 44 69 2,197,477 4/ 1940 Lyons et al 4477 2,316,012 4/ 1943 Miller 447 7 2,818,417 12/ 1957 Brown et al. 4468 2,953,587 9/ 1960 Clinton et al 4468 3,004,070 10/ 1961 Hartle 4478 FOREIGN PATENTS 590,053 10/1960 Belgium. 575,637 2/ 1946 Great Britain. 851,587 10/ 1960 Great Britain.

OTHER REFERENCES On Hydrogen Bonds Intimately Related With Electron Systems, by Masamichi Tsu'boi, Bulletin of Chemical Society of Japan, vol. 25, 1952, pp. 385-392.

DANIEL E. WY MAN, Primary Examiner.

JULIUS GREENWAIJD, Examiner.

Y. M. HARRIS, Assistant Examiner. 

11. A FUEL COMPOSITION FOR USE IN SPARK IGNITION INTERNAL COMBUSTION ENGINES CONSISTING ESSENTIALLY OF A PETROLEUM FRACTION BOILING IN THE GASOLINE HYDROCARBON RANGE, WHICH GASOLINE FUEL IS STABLE TOWARD GUM-FORMATION AND A STABLE ANTIKNOCK COMPOSITION CONSISTING ESSENTIALLY OF A LEAD ALKYL ANTIKNOCK AGENT, METHYL CYCLOPENTADIENLY MANGANESE TRICARBONYL ANTIKNOCK AGENT, AND A HYDROCARBON OIL SOLUBLE BETA-DIKETONE CHARACTERIZED BY HAVING THE STRUCTURAL FORMULA 